public class AreaAndLength {
    public static void main(String[] args) {
        double perimeter, area;
        Circle circle = new Circle(5);
        Triangle triangle = new Triangle(3, 4, 5);
        Trapezoid trapezoid = new Trapezoid(3, 4, 5);
        perimeter = circle.getCircumference();
        System.out.println("圆的周长：" + perimeter);
        area = circle.getArea();
        System.out.println("圆的面积：" + area);
        perimeter = triangle.getPerimeter();
        System.out.println("三角形的周长：" + perimeter);
        area = triangle.getArea();
        System.out.println("三角形的面积：" + area);
        area = trapezoid.getArea();
        System.out.println("梯形的面积：" + area);
        triangle.setSides(12, 34, 1);
        //triangle.setSides(3, 4, 5);

        area = triangle.getArea();
        System.out.println("三角形的面积：" + area);
        perimeter = triangle.getPerimeter();
        System.out.println("三角形的周长：" + perimeter);
    }
}